1. Field of the Invention
The present invention generally relates to the manufacture of miniature electronic devices and, more particularly, to a method and structure for the precision alignment of an integrated circuit (IC) chip on a package substrate. Such devices are typically a few microns to a tenth of micron in size and pose a critical problem in precise alignment during manufacture. The invention has particular application to the manufacture of optoelectronic (OE) devices. The technique permits, for example, precision laser-to-fiber or waveguide alignment in miniature OE devices.
2. Description of the Prior Art
The manufacture of miniature optoelectronic (OE) devices requires the precision alignment of optical devices such as lasers, detectors and lenses to optical fibers or waveguides. Such devices are in increasing demand in a variety of applications including communications and instrumentation. However, as optical devices are made increasingly smaller, the ability to quickly and easily align the optical components with precision has become increasingly difficult.
Generally, the prior art involves active or optical alignment steps in the assembly of an optoelectronic module. This type of operation requires that the device chip be electrically contacted and powered which is not possible in certain packaging configurations. Examples of the prior art techniques are disclosed in U.S. Pat. Nos. 4,807,956 to Tournereau et al., 4,764,983 to Walter, 4,756,590 to Forrest et al., and 4,755,017 to Kapany and in Japanese Patent No. 1-88404 to Hiroshiwada issued Apr. 3, 1989.
Other approaches have been taken in the prior art that do not require electrical connection to the device chip. One such approach is illustrated by U.S. Pat. No. 4,650,276 to Lanzisera et al. which describes a package that employs a cylindrical geometry to assist with alignment.
Another approach is described in U.S. Pat. No. 4,841,225 to Meyer. Meyer uses a digital capacitance system involving many electrodes resulting in a relatively complex structure which requires contact to both parts.